class Employee:
    count = 0

    def __init__(self, name):
        self.name = name
        Employee.count += 1

    def sayHello(self):
        # Employee类中的sayHello方法
        return f"Hello, I am {self.name}, an employee."

    @classmethod
    def get_count(cls):
        return cls.count

class CEO(Employee):
    def __init__(self, name):
        # 使用super调用父类的构造方法
        super().__init__(name)

    def sayHello(self):
        # CEO类中的sayHello方法，同时调用父类的sayHello方法
        parent_hello = super().sayHello()  # 调用父类的sayHello方法
        return f"{parent_hello} I am also the CEO."

# 测试代码
if __name__ == "__main__":
    emp1 = Employee("ZhangSan")
    ceo1 = CEO("LiSi")

    print(emp1.sayHello())
    print(ceo1.sayHello())
    print(f"Number of employees instantiated: {Employee.get_count()}")
